Imaging (and imagining) High Arctic Lakes

Guest post by Alexandre Normandeau

Maps of the lakes showing the detailed bottom bathymetry.  Blue and purple colours are the deepest areas.  

High Arctic Lakes are commonly used for environmental reconstructions because they are particularly sensitive to climate change. The Cape Bounty Arctic Watershed Observatory is probably one of the best examples of research sites that has shown the effect of climate change on landscape disturbances. The study of lake sediments can also provide information on natural hazards such as earthquakes and extreme flood events.  Ice cover is so pervasive on these lakes that it sometimes takes many years for conditions to occur that allow us to look into the lakes with modern research equipment.  After trying two previous years, in August 2015 we were finally able to finish surveying the lakes.

To analyze in great detail the history of natural hazards and climate change in the region, we brought very high-resolution echosounders in the High Arctic to map the bottom of the Cape Bounty’s lakes. These instruments emit soundwaves that travel to the bottom of the lake, and are reflected from the lakefloor before being recorded back by the echosounder. While commonly used echosounders are singlebeam (e.g., fishing echosounders), we use multibeam echosounders. This allows us to "see" on a 150° angle on each side of the boat, providing a complete image of the lake floor, similar to what Google Earth does for the land. These instruments are typically used on large research vessels and in accessible locations (near a road or human infrastructures). It was thus quite a challenge to bring our scientific equipment to such a remote location that is Cape Bounty. In collaboration with Université Laval, instead of using a large research vessel, we managed to fit our echosounder on a 7.5 m long zodiac. It is the first time that such an high-resolution mapping of lake floors is accomplished in the High Arctic.

Matt Gillman (M.Sc. student) on the Zodiac with the echosounders used in the High Arctic.

The data collected during the summer of 2015 was then corrected for vessel motion, lake-level fluctuations, sound refraction into the water, etc. The processed image of the lake-floor (Fig. 2) allowed us to understand sedimentary processes related to climate change (sea-level fluctuations, glaciations) and natural hazards (mass movements, floods).

Life at Cape Bounty

Guest post by M.Sc. student Amanda Schevers

The best way to carry the stand for the precipitation collectors. This is at the top of the West River catchment, I’m just about to install the final collector. 

I never thought I would ever consider battling snowstorms, bone-chilling winds, and sub-zero temperatures for an entire summer to be so rewarding and fun, yet somehow I ended up at Cape Bounty. Despite hearing stories from past students, seeing pictures, and reading more papers than I can remember, I still managed to be completely shocked when I hopped off the plane onto the lake ice. No pictures will ever do this place justice.

            But why am I here, in an uninhabited island in the middle of the High Arctic? Sometimes, when I get caught up in the small details of things, stepping back and re-reading my research proposal helps remind me what I am actually trying to accomplish while I am here (which, by the way is for a total of 64 days). We’ve heard all about climate change and how much it will change the world we live in, but how exactly is it going to change the surface water we, and countless aquatic ecosystems rely on?

To help answer this question, I’m going to be monitoring two rivers and their respective watersheds. This may sound easy, but it means I’m going to end up hiking 15-20 km carrying 10-12 litres of water every single day. Luckily I have PhD candidate Casey to help me out. We installed a network of monitoring stations, wells to collect subsurface water, and four precipitation collectors across the landscape. My first week at camp was spent out on the tundra, getting to know the land, the equipment, and getting a taste of the wide range of research that occurs at Cape Bounty.

            One of the best parts of hiking such a large area every day is the chance to see so many incredible things. Hiking up through snow lined channels, stopping to admire the approaching wolves, caribou, and muskox, and checking out all the bones scattered across the tundra are some of my favourites.

Before installing stations, we decided to walk up the East river channel. Water creates some pretty cool features. 

            Life at camp hasn’t been too shabby either. We’ve managed to bake a giant cookie, brownie, and apple crisp all in a frying pan. After a long, cold day in the field and in the lab a relaxing evening with dessert and camp stories are the perfect way to end the day. 

Probing the depths of the lakes

One of the interesting things we are doing at Cape Bounty is trying to understand the contributions of groundwater to the lakes.  This is something that is very subtle and hard to measure, so we had a number of approaches to deal with this challenge in 2016.

Maddie Harasyn sampled 21 different locations in the two main lakes during the spring and summer.  We located these sites from the detailed bathymetric mapping that Alexandre Normandeau completed in 2015.  This allowed us to find the best locations to test for the presence of groundwater seeping in over the winter.

2015 Bathymetry from sidescan sonar (from Normandeau et al. 2016).  Purple and blue colours represent the deepest areas of the lakes.

Measuring the water at the bottom of the lake is a real challenge.  We use instruments that are lowered on a rope down through the lake from the ice cover.  Imagine putting something the value of a car on the end of a $5 rope and you get the idea!  We slowly lower the instrument as it collects data at 3-second intervals.  That part is very standard.

The problem is that we want to avoid touching the bottom sediment because this will disturb the last measurements and contaminant the water samples with sediment.  In 2016, we avoided this by using a live video feed on the instrument.  So as one person lowered the instrument, another carefully watched the screen.  To know when we were near the bottom, a flashlight was directed downwards.  As it approached the bottom, the beam of light came into focus and then became very small, alerting us to stop in time.

The CTD-video-light-water sampler unit.  All designed to go through a hole in the ice.

In practice, this system worked quite well.  We were able to use a fish finder to know when we were approaching the bottom (the instrument appears as a big fish) and to turn on the video system.

We are working on the results now, but this effort appears to have been worth the trouble.  It is all part of the challenges of working in the Arctic and doing research.

Tundra Times

Posted by CBAWO M.Sc. student Matt Gillman

Teamwork is a large part of the scientific investigations that take place at the Cape Bounty Arctic Watershed Observatory (CBAWO) here on Melville Island, Nunavut. As a result, a given day may entail assisting in running an ice auger through 2 metres of lake ice so that a sediment core may be retrieved for a limnological view into paleoclimatology; or possibly hiking over tundra to collect soil and/or surface water for hydrological- or biogeochemical-based projects; or maybe collecting atmospheric gas samples with the purpose of investigating greenhouse gas emissions and drawdown due to vegetation; or grabbing stream water samples for sedimentological work; the list goes on.

My work here is focused on improving our understanding of how subsurface hydrology and hydraulics determine the delivery of water and nutrients to High Arctic Rivers. I am particularly interested in late season delivery of subsurface water and nitrogen, both of which act as controls on water quality. From this work I hope to provide information which may be applied to resource management decisions concerned with High Arctic water security, as well as future scientific endeavors aimed at building on our understanding of northern hydrology.

Now that the river is thawed and subsurface flow of water is becoming more abundant, my work in the river system consumes most of my days. Such days involve collecting solute and temperature data along the length of the river to look at the location of subsurface inflows, collecting water samples to assess the chemical composition of waters in soils adjacent to the channel, and measuring water table levels in sampling wells to map out the hydraulic conditions near the river.

Research aside, the landscape and wildlife at CBAWO are amazing. A photo can rarely give justice to the rolling hills and bedrock outcrops of the tundra. Regardless of how rough one’s day is going, it can normally be set right by a brief look around as reminder of setting. Elusive as they may be at times, the wolves, caribou, muskoxen, and arctic foxes are always a neat surprise to come across. 

A muskox enjoying some beautiful weather on the western bank of the Boundary River, Melville Island, NU.

Having had rare encounters, the animals on Melville Island have little fear of humans and are quite curious. The muskox seen in the photo here was content to watch us work from the opposite bank of Boundary River, a river which drains a lake on the boundary of Nunavut and The Northwest Territories.

As a whole, I am thoroughly enjoying the beginning of my first full (I spent a couple of weeks here last summer) field season conducting Arctic-based research. I am lost for words to describe how neat it is to be here.

Vegetation research at Cape Bounty

A guest entry by Sean Arruda (newly-minted M.Sc.)

My research focuses on the impacts of climate change on Arctic plants. For example, air temperature in the Arctic is increasing faster than anywhere else on Earth which is also expected to cause changes in the amount of rain and snow that falls in particular regions. If more snowfall occurs during the winter, leading to deeper snow, how will this extra snow effect the way plants grow in the following summer? And what if the same plants are also exposed to warmer summer temperatures than average? Does the insulating effect of deeper snow benefit the plants beneath, more than the plants that live beneath an average snow pack? Since deeper snow takes longer to melt away in the spring, does this lead to a shorter growth period for plants, or does the growing period shift so that plant development occurs later than plants under average snow conditions? Do warmer temperatures lead to changes in plant photosynthesis or productivity?

In order to attempt to answer some of these questions a long term experiment was set up at Cape Bounty to mimic some of the changes which are expected to occur to the Arctic climate. The International Tundra Experiment (ITEX, for short) has sites located in every Country within the Arctic which use the same methods for monitoring plant growth and abundance, as well as for experimentally manipulating the climate. At Cape Bounty, we manipulate air temperature by using open-top chambers (OTCs; image below). These chambers act like small greenhouses, warming the air inside by trapping in some heat. We also set up snow fences which trap windblown snow and let it accumulate about three times deeper than the average snow depth. We are able to compare between every combination of snow and warming effects by having plots exposed to both snow and warming, snow only, warming only, and some plots that remain in normal temperature and snow conditions. 

Throughout the summer, I spend a lot of time crawling around on the ground staring at plants. I monitor the date that specific individual plants begin to turn green, to flower, and to turn brown or red in the autumn. I do this in order to determine whether these warming and snow treatments are impacting the way plants grow, and also to determine whether specific species of plants are impacted more than others. I also measure how productive the plants within each plot by measuring how much carbon dioxide is being emitted to the atmosphere from the soils/plants, and how much is being removed from the atmosphere by the plants themselves through photosynthesis. We do this in a number of ways.

When I arrived this year on June 8, there was still very much snow throughout the landscape, and especially behind the ITEX snow fences! Since one of my goals this year was to monitor when each of the different treatment plots became snow free, and there was so much snow, I had time to take care of a few other tasks. One of these included setting up a special type of meteorological station which measures carbon dioxide changes in the atmosphere. CO2 concentrations in the winter time are higher than in the summer because there are no green plants growing yet. Once the snow melts, plants begin to photosynthesize, a process which removes CO2 from the atmosphere to use for plant growth. This removal of CO2 is so significant that it’s noticeable when you measure the concentration over the entire spring and summer. CO2 also gets emitted into the atmosphere from the soil. We’re interested in this CO2 concentration because it has been increasing significantly over the past several decades, and seem to be causing Earth’s temperature to increase through a process called the greenhouse effect. This station, seen below, measures the CO2 concentration continually throughout the summer. 

 Wildlife and Landscapes

At Cape Bounty there are no roads, no permanent buildings, no electricity (other than from a gas generator), no internet or email, and no phones. We are totally isolated and we are the visitors here, guests among the Birds, Lemmings, Caribou, Foxes, Muskox, Wolves, and even the Polar Bear! This is there home, and getting the chance to visit this place is something that I never take for granted.

Every day we see several of various bird species who live here. One of the common birds, two of which seem to be possibly nesting nearby because we see them almost daily, is the Brant, which is a type of goose. We’ve also seen the Snow Bunting, Lapland Longspur, King Eider, Snow Goose, Harris’ Sparrow, American Golden Plover, Jaeger, and the Rough Legged Hawk (below). This year I’ve made a point to try to identify and photographs all the different birds I’ve seen. 

On more rare occasions we sometimes get the honour of seeing herds of Muskox. Often too far away, I’ve counted herds up to 25-30 individuals. On this rare occasion, we saw the herd 2 or 3 km away in the distance as we approached one of our study sites. About 50 meters away, just on the other side of a river, an object that we all just assumed from a distance was a boulder turned out to be a single Muskox, possibly standing guard, keeping an eye on us? I'm not sure why he was so far from the herd, but he didn’t seem to mind posing for some incredible photos that day!

More often than you might think we are visited by three wolves. They never seem too interested in us, and they have plenty of Muskox and Caribou to eat so they have never been a problem to us. They tend to visit our research sites, mark their territory, and move on, often never even looking at us while they do their rounds. On some occasions they come to our camp and remind us of their presence. These animals are incredible and its amazing to get to be able to see them like this in their natural environment. The feeling you get when you get to stand there and look at a wild Arctic Wolf from 30 meters away is like nothing I’ve experienced before, and sometimes its nice to not have a camera and just take in that moment. I have a lot of respect for any animal who can survive here year round, but the Wolf is by far my favourite.

Lastly, the scenery and landscapes are unexplainable. No matter how many photos I take, none can really capture what it’s like to see this place with your own eyes. The photos below is from one of my favourite location and scenes here at Cape Bounty. On top of this plateau, the bedrock juts out forming these huge pillars. From here you can see both of the lakes and the ocean as far as the horizon. Right now there is so much contrast on the landscape between remaining snow packs, meltwater, distant greening valleys and rivers. Hiking along this ridge really makes me appreciate the opportunity to come here and do science. It makes the long, cold, tiring, days carrying gear seem like nothing when these are the views we get to see every day. 

Day in the Life of an Arctic Scientist

(Contributed by CBAWO student Maddie Harasyn- Queen's University)

Science in the Arctic has turned out to be really fun! I have been here for just over two weeks and I’m actually starting to get used to the Cape Bounty routine. It usually begins with waking up at 7:30 AM to the bright light shining through the fluorescent walls of the tents we all sleep in. Then the whole crew migrates down to the Weatherhaven (what we call our mess tent) for coffee and a breakfast of either oatmeal or pancakes. We typically add excessive amounts of toppings to our breakfast to change it up a little – peanut butter, Nutella, raisins or on special mornings M&M’s. Over breakfast, we talk about all of our schedules for the day.

My schedule involves walking down to the river beside our campsite at 9 AM and collecting water samples. I then filter the water samples to measure the amount of suspended sediment, dissolved oxygen and ions in the water which involves three separate filtering processes. Often other researchers in camp offer to help me filter, as we all help out each other when we can! I then hike out to the three smaller sub-catchments that feed the river which I just sampled and collect the same water samples at each, which is about an hour and a half hike. We always go out in pairs for safety, so the hike is filled with good conversation and lots of laughs. We often find cool things on our hikes as well, like interesting rocks or full skeletons of Muskox.

Then back to filtering in our lab tent, which occupies time until lunch rolls around. For lunch, we often make soup, Kraft Dinner or eat copious amounts of peanut butter and jam on Ryvita crackers. My afternoon often consists of helping others with their research projects – like installing sensors, or hiking up to one of the sub-catchments to collect data from the loggers recording data across the landscape. It is very interesting to learn what other students are studying up here, and how their projects are coming along. Everyone has very interesting and very diverse topics, which makes every day different and exciting. To end off the day, I complete my final rounds of water sample collections at all of the sites, and filter everything before dinner. Some dinner favorites are spaghetti, burritos or chili. Over dinner, we chat about what we accomplished during the day and neat things that we all found out on the tundra. Then we head back off to bed, in the same brightness which we woke up to.

Hiking to East Lake to collect water samples.

My personal project is looking at the water chemistry in the East and West Lake to the south of our campsite. A previous researcher discovered that small depressions exist in the bottom of the lakes, which could hint that groundwater is seeping into the lakes via these sites. My project is focused on determining the source of these depressions, which I will do by studying the water chemistry in each depression. This is done by drilling holes in the lake ice, and lowering a device down the water column slowly that measures depth, electrical conductivity, temperature, dissolved oxygen and turbidity. Water chemistry samples are also collected at the bottom of each site, to be analyzed for ions and isotopes back in the lab. After lowering this device at all 22 sites, the data can be viewed on one of the lab computers and studied to help hypothesize what may be occurring at the bottom of the lake at these sites.

So far, I have found that the East Lake has mostly uniform conductivity throughout the water columns at all of the sites, whereas some specific sites in the West Lake show an increase in conductivity and decrease in dissolved oxygen with depth in the lower water column. This could suggest that groundwater is entering the lakes through these depressions, as groundwater would have a higher concentration of dissolved ions which increase the conductivity of the water at these sites. The water chemistry analyses and historic records of the disturbance patterns in this area will help consolidate this hypothesis, which will be completed as part of my thesis back at Queen’s throughout the final year of my undergraduate program.

Both lakes we are studying can be seen above: East to the left and West to the right.

Snow melt- and rain?

The 2016 snow melt season is nearly over now.  It goes by very quickly and is usually done in a few weeks in June.  Conditions this year were initially a bit strange.  There was really not very much snow and things started to brown very fast once the melt began in early June.   The West River was flowing by June 6, which is almost the earliest we have seen since 2003 (2005 was the earliest, by a day.  Similar limited snow cover).  What was unusual was that we had several days of heavy rain in early June just as the melt was starting.  Aside from the shear discomfort of driving rain and wind on snow machines, this is an unprecedented event in our time at Cape Bounty, and rain is very important as it usually really speeds up snow melt because the rain has a lot of heat in it.  We'll have to wait for the numbers to say what the real effect was, but a strange start to the season.

Here are some photographs to compare how much the timing of snow melt has changed over the years.

In 2003, when we started, snow melt peaked around July 3.   This is what the East River looked like on June 27 as flow was just starting:

In 2005, snow melt peaked around June 8.  Here is the East River (looking towards the lake) on June 10.

The difference in spring snow melt has been nearly a month over the period we have worked at Cape Bounty.  That may not sound like much, but consider that the melt season usually only lasts until late August.  In warm years (like 2005, and so far 2016), the melt season is nearly 50% longer.  

So is 2016 really going to be a record warm year in the Arctic?  Some recent research suggests that we should not necessarily expect this, but it is not a simple answer as you will see.

2016 Reseach season: snow, soil and ice

This blog has been quiet for two years- hard to believe how fast the time went by.   We'll try to post more frequently, especially now that the field season is underway.

We opened the camp on May 18 and found the tents and equipment in generally good shape.   Conditions were already looking unusually warm based on weather from other stations in the area, and a pilot mentioned that he saw little snow on Melville Island while flying over in March.  

When we arrived, there seemed to be a lot of snow, especially around camp where we had to dig it out.  However, when we did our snow survey, we found it was quite the opposite.  Snow is a funny thing, you just can't measure it in one spot.  It blows around all winter and the depth tends to be quite different from place to place.  Each year we carry out a snow survey that involves 28 locations in the river basins and at each location, we measure depth in ten spots along a line.  We also collect snow samples with a metal tube and weigh the snow to determine how much water there actually is in the snow.  This gives us a way to calculate what hydrologists call the "snow water equivalence", or SWE (s-whee).  One way to think of SWE is how much water would be left on the land if you melted all of the snow.  It is measured as a depth, so you can think of the depth of water for a given SWE.  

The snow at CBAWO this year was very limited, the least we have measured since 2005.  It was 49 mm, about 60% of a typical year.  In many places, the snow was just a thin covering over the soil.  That indicates that there is very little water on the land for runoff this spring, something that is very important for many of the systems we monitor.

One of the things that we were interested in sampling this year was the frozen soil to see how much water was in it and how ice was formed the previous winter.  This affects how the soil thaws and how the water will flow in the soil.  Many researchers recover samples of the deeper permafrost, but this soil is not really permafrost, as it almost always thaws.  We refer to this as the "active layer", or the part of the soil that thaws during the summer.  As the name implies, this is the part of the soil where a lot of important things happen:  plants root, water moves and changes properties, and an important ecosystem of microbial life recycles dead plant matter and supports vegetation growth.  

To sample the frozen soil, we use a power auger and a hollow bit that cuts down and brings up frozen soil material.  The auger is big, powerful, and has a mind of it's own:  when it hits a rock, it can stop dead and throw the people operating it.  We give it a lot a respect and have affectionately named it 'Taz', after the Tasmanian Devil in the cartoons!

The frozen soil is pretty neat to look at.  This photo shows a section from 60-75 cm depth, and you can see some clear ice lenses and structure starting to appear.   Ice formed in these lenses late in the autumn and will only thaw late this coming summer.  When it does, the water released will be able to drain out, but we find the quality of this water is very different from snow runoff.  As you go deeper, there is even more ice, sometimes just ice for intervals of 10 cm or more.  

These samples will be analysed for their water content and we plan to get images of the ice structure while they are frozen using a special scanner like the ones they use in hospitals to image bones.  We hope by understanding how water is stored and moves through the soil at different times of year, we can better predict how climate changes will affect water in the High Arctic, and how this will contribute to the stability of the landscape and ecosystem.

And now to tease with an image that looks like something out of a movie.  No, it is not some futuristic weapon.  We actually put that underwater in the lakes to learn more about what is going on at the bottom.  That is a story for another time.  Thanks for following.